Homozygous tobiano??

[Becky]

I just got this little 29" mare and I would swear she would be homozygous for tobiano from the spots all over her. However, I had her tested and she is only heterozygous tobiano according to Animal Genetics in FL. Now, I do think the tobiano test isn't all that conclusive if I remember correctly. It's not 100%. But..... look at those spots!

 

[Bonny]

I had a large Paint mare with ALL the homozygous signs...but she was also heterozygous. I like to think of the spots as a Bonus..lol.

She sure is a pretty mare!

 

[End Level Farms]

I have seen a lot of big and small with all the spots and no homozygous.

And then my homozygous mare you NEVER EVER would guess that she is.

She just looks like a plain jane tovero. Blaze and blue eyes. But shes homozygous.

 

[Joanne]

Becky I would say the same thing except the spots on the legs bother me. I have never seen leg spotting on any of my homozygous for tobiano horses.

Is there any appaloosa in the pedigree??

 

[Bonny]

Leg spots are called dorsal and ermine spots, also a sign of homozygous...or not lol.

I was told that the jagged edges where the whie meets the brown is a sign of sabino.

 

[Songcatcher]

Interesting markings. Normally would indicate homozygous, but not always. I had a filly a few years ago that I would have sworn was homozygous from her markings, but she tested heterozygous.

So, can we see some more full body shots?

 

[Becky]

Is there any appaloosa in the pedigree??

Joanne, no, no appaloosa in her pedigree.

I've had sabinos/splashed white/tobianos with 'ink spots', but they've generally been located on the lower part of the belly. None all over like this little mare has. She has no face white and dark eyes.

Freeland, here are some more pictures I took today after giving her a bath and trimming her up. She is F-A-T, but cute!

 

[Joanne]

Becky send the photos to Animal Genetics attention Rolf and ask if they could please rerun the test for you.

There are human errors and maybe this is one of them.

There is no cost to you and they already have the sample.

Keep us posted on the results.

 

[rabbitsfizz]

Just goes to prove there is NO way of knowing by looking!!!

Very pretty mare though, so who cares????

 

[Jill]

I think the lower leg "spots" are distal spots. They look so neat on her!!! My riding horse, solid with a star and short socks, has them.

The advice to have the test re-run makes sense to me. I would have really thought her homozygous based on her body's pawprints!!!

 

[rabbitsfizz]

Jill, the "paw prints" actually have no relation to Homozygosity...it was merely that a number of animals, before the testing came out and proof could only be got by breeding, that were or appeared to be H/Z had the paw prints.

It is, however, just coincidence.

 

[Jill]

I never knew. I've always "heard" people remark that the pawprints "surely" indicate the horse is homozygous. As a die hard solid color girl (by far my favorite is solid color), I just never seem to get my head around the pinto genetics and terms. That mare though is very neat looking with her unusual markings

:yes

 

[Becky]

Jill, the "paw prints" actually have no relation to Homozygosity...it was merely that a number of animals, before the testing came out and proof could only be got by breeding, that were or appeared to be H/Z had the paw prints.It is, however, just coincidence.

Though the 'ink spots' and 'paw prints' are not a requirement for a horse to be homozygous for tobiano, all the H/Z horses I've had, including two of my current sr stallions, have them. With the number (and location) of spots this little mare has, I sure would have thought by looking at her she would be H/Z. Goes to show you can't tell by looking! But I will have her retested just to be sure.

 

[srpwildrose]

She sure does have the "look" to be H/Z.

I would also test her again, just to be sure!!

I

her Becky.......congrats on the new purchase. I'd like to have a pretty girl like that in my back yard!!

 

[horsehug]

Homozygous or not, Becky, she is adorable!

Susan O.

 

[Baydreamfarms]

A breeder I know was talking to the UC Davis lab about a filly she bought and had tested. She was told that since she had the paw prints she was homozygous. Well the lady at UC Davis said that there is no marking that will show a horse to be homozygous. Only DNA testing to prove it. She said somewhere down the line someone said that those marking were proof but they are not.

The Lady at UC Davis also said that she has had to rerun tests many times and they come back that the horse is not homozygous. So there is no way to tell just by looking at a horse.

 

[sedeh]

I would have been surprised also!! She certainly looks like she should be homozygous! Nice mare regardless!

 

[rabbitsfizz]

The lady at UC Davis....she is right!!!

There is no way to tell by looking, as I said, it is coincidence that the H/Z horses people have had have the paw prints.

I too have heard all the stories but this "myth" was blown out of the water some time ago, the first test for Tobi was only accurate for H/Z so a lot of debunking went on then.

I know it is hard to let go of these ideas, but H/Z Tobis do not have to have paw prints they do not even have to have generally accepted Tobi markings.....and I am sure Freeland has one or a picture of one somewhere, he usually does, but two white socks behind and no paw prints in sight can still be H/Z Tobiano.

None of this stops that being a very nice mare indeed!!